Lamina VII and VIII neurons of the S2 segment bilaterally projecting to the C6 segment of the spinal cord in the cat.
Intracellular and extracellular recordings of antidromic action potentials were applied to investigate neurons of the S2 segment projecting to the C6 segment of the cat spinal cord. The cell bodies were located in laminae VII and VIII of the gray matter while axons ascended in lateral funiculi. Thirty-two out of the total 45 neurons were found to project to the C6 segment bilaterally, seven ipsilaterally and six contralaterally. The axonal conduction velocities were in the 42-96 m/s range and in some neurons were significantly lower in distal parts of axons, supposing that some neurons may give off collateral branches to various segments of the spinal cord. It is discussed if the investigated neurons form a part of the propriospinal system or if their cervical projections are only collaterals of long tracts ascending to supraspinal levels. The organisation of the presented connections between spinal enlargements indicates their contribution in complex mechanisms of co-ordination of movements of the limbs.
Krutki
P
P
Department of Neurobiology, University School of Physical Education, Poznan, Poland.
Mrówczynski
W
W
Grottel
K
K
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D001369:Axons / Q000502:physiology; D002415:Cats; D009474:Neurons / Q000502:physiology*; D013116:Spinal Cord / Q000033:anatomy & histology / Q000166:cytology / Q000502:physiology*